In industrial plants it is common practice to handle materials of all kinds by means of cranes and derricks, and particularly by means of overhead travelling cranes. These overhead cranes cover, in their travel, a large area of the plant footprint, and consequently, pass and carry their loads over the workers below. Thus, the workers are constantly subjected to the hazards associated with movement of the overhead cranes and their loads. Safety measures are often used in order to alert workers located below the cranes to the presence of material being passed overhead.
When products are being transported through the use of a crane, it is common for damage to the products to occur. The most common occurrence of such damage involves the loading and unloading of the goods. Mechanisms that are able to aid the crane operator in the placement of the product can help to minimize the problem of damaging the cargo being loaded and unloaded. However, many mechanisms that attempt to aid the crane operator require that the operator shift attention away from the product and reference a secondary instrument used to provide feedback.
U.S. Pat. No. 1,712,650 is directed to a safety device for overhead cranes. The safety device includes a light projector used to project a highly concentrated intense spot or beam of light upon the floor of the shop at a desired point relative to the crane load. Such a spot or light will travel over the floor as the crane moves and will define the path traversed by the crane load. The projected light is intended to warn of possible danger of the movement of crane loads overhead. Such a device is limited to an intense spot beam that is to be projected onto the shop floor in relation to the relative location of the crane or load located overhead.
U.S. Patent Application Publication US 2012/0144682 is directed to a device for locating a load in lifting plants. A projector may be used for assisting with a lifting plant. The device for locating loads is designed to be applied to a cable- and/or chain- and/or hydraulic-type lifting plant, in which the plant includes a lifting system to which a gripping element for a load is connected via a cable or chain system, and is provided with a projector for projecting visual indications correlated with the position of the displacements of the load.
U.S. Pat. No. 6,115,129 is directed to a Laser Guided Loading System. The system utilizes a pair of lasers positioned on a cargo pick-up unit that are aligned to produce beam lines that intersect at a known height, h, below the bottom surface of the cargo. As the cargo is lowered onto the surface, the laser lines appear to move towards each other. When the laser lines overlap, an operator knows the cargo is positioned at the height, h, above the surface. An additional laser is oriented in the diagonal direction so as to give the operator an indication of the distance between the cargo and the bulkhead.
JP Patent Document 05-229784 is directed to an Under-Crane Safety Monitoring System wherein a laser scan means projects a conical colored laser beam film under a member transferred by the crane boom. The laser scan means are controlled by a control device to let an inclination angle of the laser beam film follow the movement of the member. The laser beam film provides a visual signal of the movement of the member.
What is needed is a system that is able to provide for an efficient manner of aiding the crane operator in loading and unloading cargo through means of a system integrated with the crane control system while also providing the workers below the crane with a safe working environment.